Metal injection molding (or MIM) is a relatively cost-effective manufacturing process used to produce parts or components with complex shapes from materials such as metals, metal alloys, ceramics, cemented carbides and cermets (ceramic-metal composites), among others. MIM may be used to produce metallic and/or ceramic components with more complex shapes than could be produced using traditional manufacturing techniques, such as pressed powder sintering, investment casting, turning and machining.
The typical MIM manufacturing process involves several steps generally starting with the formation of a feedstock, which is comprised of a metal or ceramic powder(s) combined with a binder to produce a homogenous mixture. This feedstock is then injected into a mold to produce a “green part” that takes the shape of the mold. Once formed, the green part is removed from the mold, allowed to rest for a period of time and is then “debound”, meaning the binder is removed from the part to leave the material powder in the shape of the part. The debound part is then sintered at a high temperature to cause the particles of the material powder to partially melt, bond together and form the completed part. In certain circumstances, a finishing operation is then performed on the completed parts (such as electroplating), however, these finishing operations may be considered as being separate from the MIM manufacturing process.
A deficiency with the existing MIM manufacturing process is that it is not always possible to manufacture complex shaped parts having certain geometries or characteristics (such as those having a hollow center or a portion consisting of a material in a porous state).
In light of the above, it may be seen that there is a need in the industry for an improved MIM processing method that alleviates, at least in part, the deficiencies associated with existing. MIM manufacturing processes in order to make it easier to manufacture components having certain desired geometries.